Sigma 300mm f4 APO (chipped) TC compatibility

Discussion in 'Canon EOS' started by TriggerHappy, Jun 9, 2017.

  1. I have an old Sigma 300mm f4 that I bought back in the film days. It wasn't fully compatible with the digital bodies so I recently had it chipped. It works like a charm again. The lens is reasonably sharp at f5.6. It has a distance window and a lens hood. Overall - it's not a bad lens. I'm considering getting one of the old teleconverters (the EX x2.0) which in theory should be compatible with the lens I have. I will loose autofocus and exposure information according to Sigma.

    However, I guess this applies to a non-chipped version of the lens. Is there a risk of damage if I try the TC? It will effectively be a f8 lens so I guess I won't care that much if I cannot change the aperture for instance.

    An attractive, and 10-times as expensive, solution would be to get the Canon EF 300mm f4 IS version and a teleconverter to go. I would get the compatibility and the IS... Is it sharper?
  2. Most likely (depending on which model Sigma we're talking about, exactly) an ex. cond. (or better) Canon L IS lens will be somewhat sharper. With the added benefit of the IS feature. Oddly, I find the recent 100-400mm L IS II to be superior at 300mm. Albeit at a price. We all get what we pay for. And not "always what we want"...
    TriggerHappy likes this.
  3. ...and I would loose 2/3-1 stop... So I'll stick to my Sigma for now. I paid about $400 for it back in the late 90's and I got it rechipped for $1 and a bottle of whiskey. I've gotten lots of use out of it.
    MarcelRomviel likes this.
  4. William Michael

    William Michael Moderator Staff Member

    On the first point: depending what camera that you have and what typical Subject that you want to capture, I would seriously consider a x1.5 or x1.4 and opt to crop in Post Production (if and when necessary), rather than use a x2.0.

    On the second point:
    not sure what you mean exactly by you won’t care so much if you can’t change the aperture – but I think you might be missing a salient point which is . . .

    You mention that your Sigma lens is “reasonably sharp at f5.6”: hence one assumes that it is LESS sharp at F/4. And perhaps your Sigma Lens is even SHARPER at F/8?

    When you plonk a x2.0 Extender on the lens, the lens/extender combination is “effectively F/8” . . . BUT that is only when the lens is wide open at F/4.

    So to get (the lens) “reasonably sharp” i.e. “at F/5.6”, the lens-extender combination will “effectively be” F/11.

    And, if the lens is even sharper at F/8, and you want to use the LENS at F/8, then the lens-extender combination will “effectively be” F/16.

    . . . this fact also contributes to considering a x1.4 or x1.5 extender and cropping in post (i.e. to lose only one stop of Aperture Speed not two.)

  5. William Michael

    William Michael Moderator Staff Member

    I went downstairs and poured a Scotch and I was thinking more on this . . .

    I am now thinking the above comment might mean: "according to Sigma when you connect old teleconverter to the lens you will lose the ability to control the aperture electronically by the camera" ?

    If my new understanding is correct, then the other comments - "effectively an F/8 lens" and "won't care much about not being able to change the aperture" make sense to me, now.


    In this case, I think that you might NOT be limited to ONLY using the lens at F/4. This is why:

    The lens, when used by itself is chipped and therefore works with Electronic Aperture control from the camera. But it is because of the old tele-converter being placed in between the lens and the camera that you lose that Electronic Aperture control. If your camera has a DoF Preview Button, (and many/most EOS DSLRs do) then you should be able to lock the Aperture on the lens at any desired stop.

    The procedure is;
    1. place the lens on the camera and select the Aperture that you ant to use.
    2. depress the DoF Preview button and hold it depressed, (this stops down the lens)
    3. whilst keeping the DoF Preview depressed, release the lens from the camera
    4. connect the lens to the Tele extender
    5. connect the tele extender/lens combination to the camera

    Provided that there is NO electronic connection through the Tele-extender, the lens will remain stopped down. The lens will release the aperture when next it is connected to the camera and electronic communications are established.

    I use this method when using EF lenses and non-communicative bellows and I see no reason why it wouldn't work with a "chipped" Sigma lens, but I make no guarantees whatsoever.


    Obviously using this method, the viewfinder will be darker but that does not necessarily mean that Manual Focusing is impossible or even a great burden, again depending upon (mainly) the camera that you have (esp "Live View") and the typical Subjects and Situation that you want to photograph (I mean that I expect this rig is not intended for fast Sports action photography as one example).

    TriggerHappy likes this.
  6. Thanks William!

    That was exactly my question. But great to know that there is a possible solution if the extender would interfere somehow.

    Why I consider x2.0 rather than the x1.4 is because I do not know if their performance differ much. Perhaps they do.

    Given the amount of pixels the 5D Mark IV has there is certainly enough to crop some, given that the original image is sharp enough. It boils down to how much "worse" the x2.0 is than the x1.4. I would really like to reach the 600mm. Reviews on the combos are scarce.

    Since I'll only gamble about £100 a pop, I think it will be worth a try.
    William Michael likes this.
  7. William Michael

    William Michael Moderator Staff Member

    haha - a nip of good Scotch obviously aided my clarity of thought.

    On the matter of the difference between the two Extenders, my experience tells me that the x2.0 will be "worse", but I understand your passion to try to quantify how much "worse" that will be.

    Thanks for disclosing that you are using a 5DMkIV.

    As one hundred quid is within a reasonable budget for you and if you really need the 600mm and if you cannot reasonably quantify or ascertain the difference between the two Extenders - if it were me - I would buy the x2.0 and give it a go.

    I am interested to know the outcome.

    Good luck.


    PS I think you'll probably keep what you buy anyway - I still have an old x3.0 Extender that I bought to mount onto a Tamron Lens that I used about 30 years ago, the lens was sold ages ago, but I kept the extender - the IQ is not very good by today's standards and I haven't used it for years, but I kept it anyway - I guess it would be handy at a pinch if I ever "needed" a really really big telephoto lens.
    TriggerHappy likes this.
  8. I'm quite sure it's because of my English. It's not my native language. Thank you for taking the time to sort my confused post out.

    Anyway, will most likely give it a go. But to be clear, the word "need" should be used loosely in my case. I rarely do any paid work and if I do - I don't need a 600mm lens. ...but I do want one... I will report the results.

    Have a nice evening.
    William Michael likes this.
  9. OOh, OOH!
    I have a nice old EF-mount Sigma 24mm f/2.8 from waaay back.
    I didn't know that Sigma would still re-chip any lenses any more.

    Where and who did the re-chipping? Pretty please?

    Or in quickly scanning over this thread, have I missed something important?
  10. I've got conflicting answers from Sigma. Sigma Sweden said that they were out of chips and Sigma USA (or was it UK) said they never did any. Sigma Sweden even went away from the phone to see if my particular chip was still in stock. There were also conflicting information on the web. Sigma Sweden at least claims that they used to re-chip.

    Anyway, I googled the topic and found a man that had re-engineered the communication and made a tiny chip that would restore the communication. My husband is a programmer by training and has an old co-worker that can do micro-chip soldering. So I was pretty much set up. The lens now works flawlessly, well at least as flawless as an old auto focus lens would work.

    Here's the link:
    Butterfly Bikers Team - Canon EOS protocol convertor for old Sigma lens

    I've had some email contact with the man behind the site and he's really nice and answers questions and seems to know a lot about Sigma lenses.

    Good Luck!
  11. tack så mycket
    TriggerHappy likes this.
  12. TriggerHappy, I also have this lens. Is there a way that I can pay to get the lens "chipped" or upgraded?


  13. Check out the link:
    Butterfly Bikers Team - Canon EOS protocol convertor for old Sigma lens

    You can get the hardware (pre-programmed) and complete instructions there. And then you just need to find someone who is good at soldering electronics who can do the work for you. Or if you're really handy yourself.

    It worked well for my lens, but that's about as much I can say.

    Good Luck
  14. Well - it works. But my god it is difficult handling such a long lens. I used to be a pretty good at clay pigeon shooting - but this was really difficult.

    Strangely enough the autofocus works, which according to Sigmas own information, it shouldn't. It is so slow though so it will hardly catch focus on anything moving. But I expected manual focus so I cannot complain. Sharpness is not that bad. I can make out the seams in the full resolution image at 100%. Some slight chromatic aberration.

    The only thing is that you need to pump the ISO up so high for a hand-held shot (also it's very windy here today), so it's starting to show a little.

    Anyway, here's one of my test shots. Sized down to 1000px everything looks nice. Might not produce A3+ prints though.
    Last edited: Jun 30, 2017
    William Michael likes this.
  15. William Michael

    William Michael Moderator Staff Member

    Fantastic about the AF.

    The sample looks crisp enough for A4 / 10 x 8 prints though. Remember also that prints often show fewer and less intense aberration than what we see on the screen

    Do you have a Monopod?

    That should help dramatically in most shooting scenarios. Best to mount it on a Tripod Collar to the lens, balancing the lens+ camera’s weight evenly. Usually no need for an Head, though if used a specialist Monopod Head is the best, this Head allows only front to back Tilting.

    A Monopod should give you the facility of 1 stop slower Shutter Speed, at the least, sometimes more.
    (What I mean is provided that the Shutter Speed remains fast enough to adequately arrest Subject Motion, a Monopod will provide enough stability to allow at least 1 Stop slower Shutter Speed and still arrest Camera Motion Blur)

    These are my experiences based upon using 70 to 200; 300; 400 all with and x1.4 and x 2.0 extenders for a range of outdoor and indoor events, mainly Field Sports and Swimming.

    TriggerHappy likes this.
  16. TriggerHappy,
    It sounds like a fun experiment and may be a nice inexpensive way to get a long 600mm lens. I suppose shooting off a tripod and using live view to focus would work well. I have a hard time getting the sharpness perfect in manual through the viewfinder. Sometimes it is spot on and other times it is slightly off. (For me) With 300mm x2 teleconverter you will be at 600mm, hand holding at 600mm even with IS takes a steady hand and faster shutter speed.

    I am all for playing with older lenses and adapting them on EOS, especially since the price is right. I wish you the best of luck and look forward to seeing you results.
    TriggerHappy likes this.

Share This Page